Line feed release mechanism



Dec. 19, 1950 o. A. LORENZ ETAL LINE FEED RELEASE MECHANISM Filed Oct. 24, 1947 INVENTOR OTTO A. LORENZ HOWARD W. YARNELL ATTORNEY Patented Dec. 19, 1950 LINE FEED RELEASE MECHANISM Otto A. Lorenz and Howard W. Yarnell, Chicago, 111., assignors to Teletype Corporation, Chicago, 111., a corporation of Delaware Application October 24, 1947,.Seria1No. 781,976

This invention pertains to printing telegraph apparatus and more particularly to platen operating arrangements therefor.

In order to prevent injury to the line feed mechanism of a page printer due to an attempt to simultaneously operate the manual and mechanical line feed functions, facilities according to the present invention are provided which automatically disable mechanical line feed during manual line feed operation. Specifically, by pressing the platen knob toward the platen, the line feed pawl will be lifted away from the line feed ratchet, thereby preventing line-feeding in response to line signals while engaging a pin on the platen shaft for manual feeding. Release of pressure on the knob will permit a compression spring to return the knob to normal, disengaging its connection with the platen shaft and reestablishing normal relationship between the line feed pawl and ratchet.

The primary objector the present invention is to provide a dual control device for the platen of a power operated page printer.

Another object of the invention is to provide manual platen rotating instrumentalities which are operable irrespective of the power operated rotating instrumentalities f the platen.

A further object of the invention is to provide a manual platen rotating means which is effective upon operation to disable the automatic line feed instrumentalities of a page printer.

Other objects and features of the invention will be apparent from the following description of an illustrative embodiment thereof, taken in conjunction with the accompanying drawing, in which:

Fig. 1 is a perspective view of the dual platen rotating arrangement according to the present invention;

Fig. 2 is a front elevational view of the mechanism shown in Fig. 1, and

Fig. 3 is a top view of said arrangement.

Having reference to the drawings wherein like reference characters refer to like parts throughout the several views, the present invention is shown as applied to apage printer of the type disclosed in U. S. Patent 1,904,164 granted April 18, 1933 to S. Morton et al., which patent is incorporated herein by reference. Only a sufficient portion of the mechanism shown in said patent is disclosed herein to permit a ready understanding of the present invention. Platen I I is rotatably supported on a shaft 12 suitably carried in the side frames of the printer. Integral with the platen H is a line feed ratchet 1 Claim. (Cl. 197 -114) wheel i3, and cooperating with said ratchet wheel is a line feed pawl l4 having a tooth l5 for engaging the peripheral teeth of the ratchet wheel.

Pawl I4 is pivotally articulated to the extremity of the vertical arm of a line feed bell crank 16 which is supported rotatably on a rod 11 suitably positioned in the apparatus. To the extremity of the horizontal arm of bell crank i6 is pivotally connected the upper end of the line feed operating link I8. The bell crank I6 and link 18 are comparable to the bell crank 249 and prising themanual platen rotating portion of the mechanism according to the present invention. Slidably mounted on the end portion of the shaft i2 is a sleeve member or reciprocator 19 which is provided with an integral flange 2i. Sleeve as is counterbored to receive a compression spring 22 (Figs. 2 and 3) adapted to be compressed between a washer 23 bearing against the end of the shaft l2 and a knob 01 cap 24 fitted over one end of the sleeve 19 and secured thereto by a set screw 25.

Shaft 12 is provided near its end with a wide peripheral groove 25 which receives the inwardly projected end of an adjustable screw 2'! suitably carried in the wall of the sleeve 19. The inner end of the sleeve 19 adjacent the flange 21 is provided with a plurality of diametrically aligned grooves 28 (in the present embodiment spaced apart) which cooperate with a pin 29 extending transversely and diametrically through the shaft 12, in such a manner that the grooves 2i are adapted to engage the protruding or projecting ends of the pin 29 to provide a positive clutch means between sleeve 19 and shaft l2, as will hereinafter appear.

Secured to the frame It by means of screws 3| is a bracket 32, having a depending flange 33 carrying a pair of horizontally aligned stud screws 36. Supported by studs 34 for slidable movement thereon through the medium of a slot 35 is a camming instrumentality 3B which is normally urged leftwardly (as viewed in Fig. 2) by a spring 3'! extended between spring supports integral with said instrumentality and said depending flange.

Instrumentality 36 is conformed at one end with 3 a camming surface 4| which coacts with the extension 42 of the pawl Hi. The opposite end of the instrumentality 36 is formed with a laterally extending portion 43 which cooperates with the flange 2| of the sleeve l9.

In the operation of the device according to the present invention, the platen is normally rotated automatically during the execution of each line feed function in a step-by-stp manner by the pawl I4 through the actuation of bell cranl;

55 by the link If! as described in the aforementioned patent. It sometimes becomes necessary to rotate the platen I! manually to adjust the paper or for some other reason while the printer is operating automatically in response to receiyed code signals. The device according to the invention is designed to achieve this result by simultaneously enabling manual operation and disabling automatic operation. To effect this result it is merely necessary to grasp the knob Z4 and press toward the'pla te'n H to thereby slide the reciprocator l9 against the action of spring 22 to "permit the clutch slots 28t0 engage'the clutch pin 29. During this process the flange 21 engages the lateral portion is of camminginstrumentality 3i; and causes the instrumentality 36 to slide on the tuds '34 thus bringing the cammin g surface At into action to raise the extension 42 of pawl l4 thereby disengaging the tooth i5 from the ratchet wheel [3 to disable the line 3 feed mechanism. Thereafter the pawl I4 merely slides ineffectively on the instrumentality 36, and by means of the clutching engagement of reciprocator IQ and shaft [2- (through pin 29 and slot 28-) the platen i i may readily be rotated manually said platen, a line feed mechanism for rotating said platen and said shaft comprising a ratchet wheel and a pawl means cooperable with said ratchet wheel, said pawl means provided with an overhanging portion, signal controlled power driven means for actuating said line feed mechanism, a sleeve carried on an extended portion of saidshaft adjacent said ratchet wheel, an adjustable screw mounted in the wall of said sleeve, said shaft provided with a wide peripheral groove to receive the inwardly projecting end of said screw, whereby the slidable movement of said sleeve on said shaft is limited, a capcovering one end of said sleeve, a compression spring disposed the bore 9f said sleeve between said cap and the endof said shaft, a pin extending transversely through said shaft and disposed a predetermined distance from the other end of said sleeve and adapted under predetermined operatns cen inns to, cooperat wi h a gned rooves in the adjacent end of said sleeve, a flange integral with said sleeve, and a pawl disengaging means slidably supported between said platen and said sleeve, said pawl disengaging means comprising a lateral projection cooperable with said flange and a camming means adapted to cooperate with said overhanging portion, whereby upon predetermined manipulation of said sleeve said camming means is callsfld to coact with said overhanging p ion t se a s id p w ean ro Said ratchet wheel to facilitate manual operation of said platen irrespective of thecontinued operation of said pawl means by said power driven means.

OTTO A. LORENZ. HOWnRD W. YARNELL.

REFEBENGES e I P The following references. are. of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 47 210 Barren pr- 1 92 694. D 1 301s, M 1 4, 1902 36.84 B la Oct 2. 1909 

